Heating device



0st. 27, 1931. R. M. HEAMES ETAL HEATING DEVICE Filed July 13, 1928 Patented Oct. 27, 1931 RICHARD, n. firmas, er Gnossa PATENT OFFICE POINTE, AND HAROLD, STAR-K, OF DETROIT, MICHIGAN HEATING DEVICE Application led .Tulyy 13,

The present invention relates in generalto improvements in the art of'V heating,and relates more speciiicallytoi-improvements in the constructionand operation .of heat treat'- ing furnaces, the .improvements being4 especiallyapplicable to heatingdevices Whereinlmaterial is subjected. to relatively high temperatures `While itl-is located in a confined zone such as a receptacle or pot.

VA general object of the invention is to prov-ide animproved heating device which is simple and durable 'in construction, and wherein the heat may be moreeffectively applied to thematerial/being treated, thany in prior 'devices of a similar character.

Itis common commercial :practice in the art of heat treating certain kinds of metallic bodies such as cap screws andbolts,` to immerse batches of the bodies in a hot solution of cyanide or! the like conlinedf in a melting pot, for a definite period of time. The standard melting pots usediforsuch purposes, areA Ordinar-ily Vformed of relatively7 low grade materialwhich is not capable of resisting destructive corrosion resulting fromthe high temperatures, for any great length of time. The cost of constructing these pots of higher grade corrosion v resisting materials, is 4too great; to Warrant the expense, in spite of the fact that-potslformed of the higher gradeof materialshave greatly prolonged lives or periodsof usefulness. The cost of such pots formed of high grade materiallis many times that ofthe standard pots which are formed ofloW grade material.

In order to eliminaterapid-destruction of such melting pots due to corrosion, the presentinvention contemplates theprovision of jackets formed of relatively thin Vcorrosion resistingA material, which may be detachably appliedtoY the entire exterior and to a portion of the interior of standard pots constructed of relatively .low grade material. These shells or jackets-areformed to snugly fit the surfaces f of the pots whichthe'y'protect, and may be mannfacturedatrelatively low cost. When the protectors Wear out, they. may be renewed from timeto tim,e,.thereby prolonging the life of the ordinary melting pot which is formed oflow grade material, manyfold, at

1928. Serial No. 292,476.

but very slight additional expense to the user. The renewable coveringsprovide a coat Vof armour for the pots, andv may be formed of commercial sheet metal' having the characteristic of edectively resisting the destructive effects of high heat.

`Besides the provision of these corrosion resisting jackets for the melting pots, the prese-nt invention contemplates provision of simplemeans for more. effectively utilizing and applying heat in melting pot furnaces. This improved result is accomplished by applying the heat in series to a-succes'sion of melting pots, through controllablek conduits formed and disposed to effectively. apply and distribute the heat. The individual pots of theseries-are moreover provided Withspecial insulating closure caps which prevent Vundesirable escape of hot gases from the-pots, but which may be readily removed to permitaccess to the pot interiors.

Thel present invention furthermore contemplates provision of means for effectively avoidingloss of material byl spilling, in case the .pots fail by corrosion or otherwise. When such failure occurs in the standard furnaces now in use, the molten material drops into thelower portion of the heating zone and the furnace must; be shutdown and permitted4 to cool.- Upon cooling, the molten material solidiiies and must consequently'be removed With considerabley difficulty: after it has solidified-and adhered to the furnace structure. `The 'removing operation frequently damages the furnace Walls, besides causing considerable loss of time before'the furnace can again be placed in operation. In accordance with the present invention,fany spilled material may be quickly removed, a new pot may be installed in place of one that fails, and the furnace may be rapidly restored to operating condition, with minimum'loss of time. Withthe improvement, all of the spilled material may be reclaimed for subsequent use, thereby eliminating Waste of materials.

These and other objects and advantagesl resulting from the present improvemcnt,.will be apparent from thefolloWing description.

A clear conception of an embodiment of i 30. tunnels 6, 7." `Each of the conduits 9, 10, 11!

- 45;. pending into each ofthe heating zones 2, 3, 4,y

' .5.5. with the aid of dies, and are readily detach- V the several features of the present invention.

and of the inode of constructing and of operating furnaces in accordance therewith,

may-be had by referring to the drawings'acvcompanying and forming a part of this spec- .iiicationpin which like reference characters Fig. 2 is aV1 longitudinal vertical sectionV through the heating device or furnace. I

Fig. 3 is a transverse vertical; lsection through the heating device or furnace. Fig 4v is a vertical section-througha melting-pot having two-of the-imp'rovedffprotecy tive jackets applied thereto. ff

v The improved cyanide-furnace speciically illustrated inthe drawings comprises a refractory structure 13 formedy of ylire brick or the like and providing a series Vfofy heating zones2, 3, 4. 4A pair of firing tunnels 6, 7 are disposedon opposite sides of the heatingzones* 2M, 3, 4 and areconnected with these zones by. means of lateralconduits 9, 10,111 which are of progressively increasing cross-sectional` area advancing along the tunnels in theV direction ofthe. flame-propagationy within the may be provided rwith a shut-off gate 24 cooperating with guid'eways 26, for'con-trolling Y the iow of hotgases tothe heating-zones 2,

3,4, and Aadditional gates 23 'cooperating with transverseY guideways 25 may/also be .provided for permitting any one-of the furnaces to= be shut down withoutfinterfering with the operation of the others. kThe opposite ends of the tunnels G,l lare provided with fuel injec-y tion'nozzles or firing devices, and'each of the heating zones 2, 3,`v 4, is provided with an' exhaust: fiue 12leading away from thevlower portion'ofthe-heating chamber.

Suspended from the structure13 and deis a meltingpot 5 the. outerv portion ofwhich is enc'asedinV a sung'.fitting,relativelythlnY corrosion resisting sh-ellw15. YThe'portiony ofi each pot 5, which `is exposed above the molten ,5.0. material. 18 therein, may also be provided'` with a protective-skirt 20forn1ed of corrosion resisting metal and snugly fitting Vvthe adjacent surface of theV pot.- The protective jackets are preferably. formed'of sheet metal.-

able from lthe pots 5.- -The metal .ofwhich' the protective jackets arecomposed, may con- Y tain corrosion resisting ingredients 'such as nickel, chromium, or silicon, andthe' combined percentages of iron, carbon,'sulphur,

phosphorus and manganese contained in the alloy,4 should be less than ninety-live percent of'theftotahalthough better results are 0b-v tainablewheii ther-combined percentages of these ingredientsv is less than f nlnety percent ljackets.

Amit access to the interior of the'pots 5'.l The such as asbestos preferablyconned in 'a shell of the total. The corrosion' resisting jackets or shells 15 may be retained in-position in any. desired manner, but they should be quickly detachable for replacement by new Disposed above Yeach of the-melting pots 5 Vand resting directly upon the structure 13, is

aclosure cap 14. rlhese closure caps 14 are independently and freely removable to percaps1`14 may be provided withlinings 21 formedofmaterial which is capable of eiiectively 'withstanding relatively high temperatures, and alayer 22 of asbestos or the like serves to retain the gases and heat within the pots.

Located within each of the heating zones 2, 3,14 directly'beneaththe.melting pot 5 therein, is a`1car16 kcovering substantially the entire'bottom of the zones, for effectingv rapid removalo'f spilled material 18.-A The cars 16 are laterally removable fromwithin the heating rzones 2, 3, 4 `,throughY side openings farmed in the structureV 13, and are' preferably lined with refractory material such yas fire. brick. The openings forpermitting insertion-.and removalo'f the cars 16 are preferably sealed bymeans of readilyv removable plugs 17 formed offrelati'vely; lightv material of heat resistant material,as shown in Fig'. 3. During normal operation of the'improved furnace, themelting pots5 encased within the shells 15 and' linedflwith .the skirts 20, are disposed withinrthe heating-*zones 2, 3, 4- as loo shown in F igsr'l, 2 and 3, and Vfuel is injected into-the tunnels 6, 7A through the nozzles 8 and is .ignited therein. The gases of combustionlproducedvby burning the fuel, pass laterally from the tunnels v6, "v through the conduits 9, 10, 11and are delivered'tangentiallyagainst theprotecting vshells 15 of the pots 5. The material 18 within the pots 5 is thus kept in inoltencondition by the application ofheat tothe pots through the shells 15. Due-to the corrosion resisting qualities ofthe protecting shells 15 and skirtsf20, the exposed vsurfaces offthese-.jackets-are kept relatively eleanat all times, thereby permitting eifective transmission of thejheat to the material 115, 18 Within the pots. The closure covers14 are of special construction, and should' be maintained over the pots 5 during normal operation of the furnace in order to retain the-heat and theg-ases therein, but thesecaps, 14 are 120i conveniently removable whenitis desired to insert a fresh batch of metallic bodies orthe like in the moltenmaterial 18 within the pots. virtue 'of the'variation'in cross-sectional area'offthe conduits 9, 10,411, andV also due to 1252 the arrangement offtheV firing nozzles 8 at opposite ends ofthe tunnels' 6, 7 uniform distribution of the heat toiall. of the zones 2, 3, 4 is insured, and vthe flues 12 serve to deliver the spent gases from the heating zones. .13.91

r of the fumes.

may be quickly removed.

If it is desired to shut down one or more of the furnaces without interfering with the normal operation of others, the conduits 9, 10, 11 and the end openings which communicate with the heating zone of the furnace which it isdesired to shut down, may be readily shut ofi with gates 24, 23, as shown. Such shutting down of a furnace may be desirable in case of failure of the melting pot therein, whereby the molten material from within the destroyed pot will be precipitated into the car 16 therebeneath. The sealing plug 17 may then be withdrawn and the car 16 containing all of the spilled material 18, rlhe material confined within the removed car may then be reclaimed and utilized in a new melting pot inserted in the furnace in place of the device which has failed.

From the foregoing description, it will be apparent that the relatively thin corrosion resisting shells not only materially prolong the lives of the melting pots 5 to which these jackets are applied, but also serve to permit more efficient transfer of heat to the material within the pots by preventing the formation of scale on the heat receiving surfaces. The skirts 20 also prolong the life of the pots 5 by eliminating destructive action The cover liners 21 and the asbestos layers 22 cooperating therewith effectively reduce the heat and material losses to a minimum and prolong the life of the covers to which they are applied. The liners 21 also prevent precipitation of undesirable scale, into the molten solution. The shells 15 and skirts 20 may be pro-vided at moderate cost and should snugly fit the pots 5 in order to insure eflicient transfer of heat to the material 18 within the pots. The shells 15, skirts 2O and liners 21 may be readily renewed from time totime, and may be formed of standard sheet metal having the proper corrosion resisting qualities.

By applying the heated gases through tunnels 6, 7 and distribution conduits 9, 10, 11 of progressively increasing cross-sectional areas located on opposite sides of the heat* ing zones 2, 8, 4, effective distribution and application of the heat is insured. The provision of insulated closure caps 14 for the individual pots, also aids in the conservation of heat and in the production of maximum efficiency. The cars 16 serve to effectively catch and to facilitate removal of spilled material, and prevent adherence of the spilled material upon the furnace structure 13. The plugs 17 additionally assist in the conservation of heat, thereby producing a heating device of maximum efficiency and of highest economy.

It should be understood that it is not desired to limit the invention to the exact details of construction and operation herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent 1. In combination, a relatively thick pot for directly confining molten material, a thin shell snugly fitting and covering the entire external surface of said pot, and a thin skirt snugly fitting and covering the internal surface of said pot above the normal level of molten material therein, said pot being formed of corrosive material and said shell and skirt being detachable from said pot and being formed o-f corrosion resistant metal.

2. In combination, a relatively thick pot for directly confining molten material, said pot having an outwardly projecting annular supporting flange at its open end, a. thin shell snugly fitting and covering the entire external surface of said pot and one side of said flange, and a thin skirt snugly fitting and covering the opposite side of said flange and the internal surface of said pot above the normal level of molten material therein, said pot being` formed of corrosive material and said shell and skirt being detachable from said pot and being formed of corrosion resistant metal.

In testimony whereof, the signatures of the inventors are afixed hereto.

RICHARD M. HEAMES. HAROLD STARK. 

